Water softening device



G. HEGWEIN 2,224,101

WATER 'SOFTENING DEVICE Dec. 3, 1940.

2 Sheets-Sheet 1 ,Filed March 11, 1938 as I ' a! I H Jnran/ap:

Dec. 3, 1940. 3. HEGWEIN WATER SOFTENING DEVICE Filed March 11, 1938 2Sheets-Sheet 2 iii. 1 i! Patented Dec. 3, 1940 UNITED STATES PATENTOFFICE WATER SOFTENING DEVICE Georg Hegwein, Dessau, Germany, assignorto Junkers. & Co. G. m. b. 11., Dessau, Germany Application March 11,1938, Serial No. 195,399

Germany March 16, 1937 in Claims. (01. 21041) To ensure the satisfactoryworking of apparatus such as boilers, storage tanks, continuous flowheaters and the like for heating liquids in which water is raised to ahigh temperature (for example over 60 C.) it is necessary that the waterto be heated should, especially if it exhibits a high degree ofhardness, be given an addition of chemicals (so-called softeners) whichprevent the deposition of boiler fur on the surfaces of the heater whichare in contact with the water. Alternatively the heater must be freed,at intervals from incrustations of boiler fur by means of specialsolvents. Thus for example numerous devices have already been evolvedfor purifying boiler-feed water which soften the feed water prior to itsadmission into the boiler.

In this connection it is known to utilise the energy of flow of theincoming water for drawing the softening agent into the water by meansof injectors, Venturi tubes or the like. In like manner it has alsobeenproposed that the Venturi tubes employed for generating the pressuredrop for automatically opening and closing the gas valves of gas-heatedcontinuous-flow heaters should also be utilised for drawing in aboilerfur solvent (such as hydrochloric acid) to be mixed with the waterin order to re-dissolve the boiler fur deposited in the heater.

The present invention relates to a watersoftening device which issuitable, in particular for continuous-flow heaters, intended to furnishboiling, hot, or warm water as may be required. In the case of suchheaters a larger or smaller amount of water is allowed to flow throughthe heater according to whether a higher or lower temperature at theoutlet is desired. 40 The amount of flow can be controlled by means of adraweoil cock or a special control device. Since the suction efiect ofan injector or the like located in the path of the flowing waterincreases and diminishes with the amount of water passing through only asmall amount of the softening agent would be drawn in when boiling waterwas drawn oil, and a larger amount of said agent in the case of warmwater if the suction pipe for the softening agent were connected with aninjector or Venturi tube without any special means of control. It is,however, desirable that the amount of softening agent introduced shouldbe in inverse proportion to the amount, and the outlet temperature, ofwater passing through the heater, because the higher said temperature,the

greater the tendency for the deposition of boiler for by the water. Onthe other hand no softening agentis needed when the water is heated onlyto about 40 (3., because in that case the formation of boiler fur isquite insignificant. So

, long as no water is being drawn oil the path from the heater to thestorage vessel for the softening agent should be closed in order toprevent the water standing under pressure in the heater from beingforced into said storage vessel. It is also desirable to provide meansfor automatically closing the passage to the storage vessel in the eventof the outlet from the heater becoming (wholly or partially obstructed,for example by impurities in the water, or by boiler-fur incrustation,in order that the pressure generated in the heater while in operationmay not force the water into the storage vessel for the softening agent.

According to the present invention a device fulfilling the saidrequirements for controlling the amount of softening agent supplied tothe waterland protecting the storage vessel for said agent from beingpenetrated by water, is furnished by locating in the suction pipeleading from the suction device to said storage vessel, a control valvewhich automatically regulates and shuts ofi the'supply of the softeningagent in accordance with the amount of water drawn oii. Said controlvalve is preferably actuated by an adjusting member (diaphragm, pistonor the like) which is subjected to theaction of the pressure in thesuction pipe attached to the suction device (Venturi tube, injector orthe like). The control valve may, however, also be controlled inaccordance with the temperature of the heated water at a predeterminedpoint inthe heater or it may be operatively coupled with thedeviceregulating the flow of water through the heater. The control valvemay be of the doublecone or sliding-piston type which when in theneutral position, determined for example by the spring-loading of theadjusting device, shuts off the passage for the softening agent butopens it fully when boiling water is drawn oil whilst again throttlingsaid passage as the fiow of water through the heater increasesand shutsit off completely when a certain maximum flow of water is exceeded, orwhen the withdrawal of water ceases. According to the invention in orderto limit with precision the control movements of the adjusting memberunder the varying action of the suction device several springs (of equalor difierent tension) which come successively into operation areemployed for loading the adlusting member. The control valve may also beso designed as to supply the water in the heater with the same amount ofsoftening agent per litre when "boiling or hot water is to be drawn off.

Several typical embodiments of the present invention are illustrated inthe accompanying drawings in which:

Fig. 1 represents a gas-heated liquid heater with an automatic diaphragmgas valve, a control valve attached to the Venturi tube and actuated bythe pressure in the suction pipe, and a storage vessel for the softeningagent.

Fig. 2 shows another typical embodiment of -a control valve actuated bythe pressure in the suction pipe.

Fig. 3 shows an embodiment in which the control valve in the suctionpipe for the softening agent is operatively connected with the draw-oficock, whilst in the embodiment shown in Fig. 4, the control valve isactuated by a thermo-sensitive device which responds to the temperatureof the water at a suitable point of the heater.

As shown in Fig. 1, l denotes the coiled-tube water pipe and H the gasburner of the heater. The cold water enters the heater through the pipel2 and is drawn off through the pipe l3. I4 is the draw-ofi cock and |5a device by means of which the amount of water flowing through theheater per unit of time, and therefore the desired dischargetemperature, can be adjusted. The cold water flows through a Venturitube IS. The suction generated by the Venturi tube at its point ofminimum cross section serves to actuate the diaphragm |1 controlling thegas valve l8 through a suction pipe l9. In addition to the suction pipeHi there is attached at the point of minimum cross section of theVenturi tube I6 another pipe 20 which leads to the control valve 2 Thepipe 22 connects the control valve with the storage vessel 23 for thesoftening agent.

The control valve 2| comprises a casing 24 provided with connectingbranches for the pipes 23 and 22 leading respectively to the Venturitube and the storage vessel. The casing 24 contains two chambers 25, 2Gseparated by a diaphragm 21 serving as adjusting member. The chamber 25communicates with the atmosphere through an orifice 28, and the otherchamber 26 communicates with the suction pipe 23. Suspended on thediaphragm 21 is a valve having cones 29, 30 which control the two valveseatings 3|, 32. The branch of the casing 24 connecting the pipe 22 isalso provided with a screw throttle 33. In the neutral position aloading spring 34 presses the valve cone-30 against its seating. 32.Coaxially ,with the spring 34 is another loading spring 35,

guided on a sleeve 36. This spring comes into operation only after' thediaphragm 21 has described a predetermined stroke.

The device functions in the following manner: To enable water to bedrawn off at a predetermined temperature the adjusting device l|5 isfirst adjusted, for example for drawing off "boiling water. The draw-01fcock is then turned on. The cold water flows through the pipe l2 andVenturi tube l5 to the heater. The suction created by the Venturi tubeacts through the pipe IS on the diaphragm" which is lifted and opens thegas valve Ill. The gas issuing from the burner II is ignited by thepilot flame II' and heats the water passing through the coil III. TheVenturi tube also creates a suction effect in the pipe 20, the resultbeing that the ii hrag TI is moved slightly towards the right, againstthe force of the spring 34, and slightly opens the attached valve 30which was hitherto pressed against its seating 32 so that the pipe 22and the storage vessel 23 are under suction. In this way a predeterminedamount of the softening agent is drawn past the cone 30 and iscontinuously mixed with the water flowing to the heater. In order tolimit the stroke of the valve 29, 30 with precision a second loadingspring 35, guided on the sleeve 36, is located inside the loading spring34. When the diaphragm 21 has described the lifting stroke (e. g. 1-2mm. according to the dimensions of the entire control device) needed forthe withdrawal of boiling water the spring abutment plate 31, mounted onthe diaphragm spindle encounters the sleeve 36. Since the suction effectof the Venturi tubein drawing off boiling water-is now insuflicient tocompress the spring 35 in addition to the spring 34, the lifting strokeof the dia- Assuming now the device I5 is now to be set for supplyinghot but not boiling" water. In such case a larger amount of water flowsper unit of time through the heater and therefore also the Venturi tube.Consequently the Venturi tube exerts a more powerful suction on the pipeand the diaphragm chamber 26 so that the spring 35 also is nowcompressed to a predetermined extent. Although the cone 30 isconsequently lifted further from its seating the cone 29, however, ismoved at the same time towards its seating 3|. The two valve cones 29,30 are spaced so that now the valve cone 29 and its seating 3| determinethe amount of softening agent supplied. The dimensions may be such thatfor drawing-off hot water, the aperture provided bythe valve cone .29and its seating is equal to, or smaller than, that provided by the valvecone 30 and its seating in the withdrawal of boiling water. The valveapertures for the time being may also be varied at convenience forexample by using interchangeable springs varying the tension of theindividual springs or arranging for the valve cones to be relativelyadjustable. Another resilient stop may also be provided forlimiting thestroke of the diaphragm when hot water is to be withdrawn.

As already mentioned it is usually desirable not to supply the waterwith any softening agent at all when it is to be heated to only about40/50 C. Consequently, for the withdrawal of warm water the controldevice must close the passage for the softening agent. This isautomatically efiected in the same way as the control in the case ofwithdrawing boiling or hot water. For drawing-oif warm water acomparatively large amount of water flows through the heater l0 andVenturi tube l6. Consequently the suction exerted on the diaphragm 21 bythe Venturi tube is so powerful that the loading springs are compresseduntil the valve cone 29 rests on its seating 3|. In this position,therefore, no softening agent can be injected.

On the draw-off cock l4 being closed the flow of water through theVenturi tube ceases. The diaphragm 21 is drawn towards the left by theloading spring 34 and thus the valve 30 rests on its seating 32. In thismanner the storage vessel 23-is protected from penetration by waterunder pressure in the pipe l2.

The control device according to the invention also protects the storagevessel 23 from penetra- 'tion by water when the heater is in operationshould an excessive pressure be set up in the Such pressure if presentin the cold water pipe l2 might cause the penetration of water into thepipe 20. However, directly the suction by the Venturi tube ceases thespring 34 moves the valve 30 on to its seating 32. If the increasedpressure in the heater is transmitted through the pipe 20 into thediaphragm chamber 26 it also increases the closing pressure of the valveso that the storage vessel is protected against any influx of water.

In the embodiment of the control device shown.

in Fig. 2, the double-cone valve 29, 30 represented in Fig. 1 isreplaced by a slide valve 33 which in the position shown, shuts off thepassage for the softening agent. In the case of the dimensions chosenthe bores 39, 40 coincide when the diaphragm performs the strokecorresponding with the withdrawal of boiling water, the plate 31 againcoming into contact with the sleeve 36. During the further movement ofthe diaphragm, corresponding to the withdrawal of hot water, the slide'valve 38 is moved further towards the right and reduces the aperture'ofthe passage. In this arrangement in order to limit the valve openingmovement of the diaphragm an additional spring 4| is provided whichtheslide valve encounters on reaching the predetermined stroke. The spring4| is mounted in the screwed cover 42 which is removable for the purposeof inserting the slide valve 38 and can be adjusted to vary the positionof the spring 4| by means of the screw formed on said cover. Theincreased flow of water through the Venturi tube when warm water is tobe drawn off pushes the slide valve 38 still further towards the'rightand thus again closes the passage completely. The movement of the valvetowards the left is limited by the contact of a flange 43 with anabutment in the valve casing.

A screw throttle 33, located in the branch connection for the pipe 22between the control valve 2i and the storage vessel 23 and is adjustableto regulate the maximum supply of softening agent. The setting of thescrew is dependent on the local conditions such as the degree ofhardness of the water, the length of the pipe connections 20 and 22, thewater pressure etc. A detachable filter (not shown) is preferablylocated at this throttling point.

In the embodiment shown in Fig. 3 the control device 2| is coupled withthe draw-off cock I4 serving'to control the volume of water flowingthrough the heater. The control device consists, like that shown in Fig.1, of a casing with branch connections for the pipes 20 and 22, leadingrespectively to the Venturi tube I6 and storage vessel 23, and of a conevalve 44 controlling a seating 45. When the cock I4 is in the fully openposition shown in Fig. 3 wherein the ;.large amount of water flowingthrough the heater is heated to about 40-50" C. the valve com: 44 shutsoff the supply of softening agent. In order to withdraw hot water, thecone 43 of the cock.

I4 is moved further towards its seating 41, thus throttling the flow. Atthe same time, through its operative connection with the cock 14' thevalve cone 44 of the control valve is lifted from its seating 45,leaving a predetermined aperture for the passage of the softening agentso that the Venturi tube can now draw the latter in. For the withdrawalof boiling water the flow of water through the heater is furtherrestricted, the valve cone 44 being thereby moved further away from itsseating so that a larger amount of softening agent can now be drawn in.In order to prevent water from passing into the storage vessel 23 whenthe valve I4 15 closed, the valve cone 44 being then furthest away fromits seating, said cone 44 is suspended on a diaphragm 48 which, on thecessation of the suction by the Venturi tube I6, is pressed upwards bythe pressure created by thewater in the supply pipe [2 or in the heaterI I], and thus forces the valve cone 44 against its seating. To-permitthis movement of the diaphragm independently of the setting of the valvel4 the two members, diaphragm 48 and valve l4, are resilientlyinterconnected by a spring clutch 49. When the valve l4"is closed, thediaphragm 48 can rise in compressing the spring 50. This arrangementalso serves to prothe suction pipe 20 and raises the diaphragm until thevalve 44 rests on its seating 45.

Fig. 4 shows another typical embodiment of the arrangement and design ofthe control valve.

In this figure at a suitable point of the heater l0 there is arranged athermo-sensitive member 5| influenced by the temperature of the waterand adapted to actuate the control valve 52 in the suction pipe 20, 22.The higher the desired and adjustable outflow temperature of the water,the higher will the temperature of the. water also be at the point ofattachment of the thermosensitive member 5!. In the drawing, said memheris designed as a bellows which expands under the influence of the heatof the water and in so doingmoves the valve to a corresponding extentfrom its seating as the water becomes hotter. In this manner, therefore,the flowing water receives a larger supply of softening agent as itstemperature rises. To prevent water from entering the storage vessel 23a non-return valve 53 is provided in the suction pipe 20,- 22 andcloses, automatically or under the pressure of pressure in said suctionline for controlling said suction line whereby the supply ofscale-preventing agent to the suction device is increased when thesupplyof water to the heater isdecreased, and the supply of scale-preventingagent to the suction device is decreased when the flow of water to theheater is increased.

2. An apparatus for applying a scale-preventing agent to the watersupply of an instantaneous water heater, comprising, in combination, asource of water under pressure, a suction device operated by the water,a suction line connecting said suction device with a source ofscale-preventing agent, and valve means controlled by the pressure insaid suction line for controlling said device is increased when thesupply of water to the heater is decreased, and the supply ofscalepreventing agent to the suction device is decreased when the flowof water to the heater is increased.

3. An apparatus for applying a scale-preventing agent to the watersupply of an instantaneous water heater, comprising, in combination, asource of water under pressure, a suction device operated by the water,a suction line connecting said suction device with a source ofscale-preventing agent, a valve in said suction line which is closed bythe negative pressure established in said suction line, and a secondvalve in said suction line which is closed by positive pressure in saidsuction line, whereby the flow of scale-preventing agent to the suctiondevice is cut off and the water under pressure is prevented from passinginto the source of scale-preventing agent.

4. An apparatus for applying a scale-preventing agent to the watersupply of an instantaneous water heater comprising, in combination, asource of water under pressure, a suction device operated by the water,a suction line connecting said suction device with a source ofscale-preventing agent, a valve in said suction line which is closed bynegative pressure in said suction line and a second valve which isclosed by positive pressure in said suction line, both valves formingtogether a double-cone valve.

5. An apparatus for applying a scale-preventing agent to the watersupply of an instantaneous water heater, comprising, in combination, asource of water under pressure, a suction device operated by the water,a suction line connecting said suction device with a source of scalepreventing agent, a valve in said suction line which is operated by thepressure in said suction line, said valve comprising a slide valvehaving a passage which is closed by positive pressure in the suctionline as well as by a negative pressure thereby said springs which comesuccessively into operation whenever the stroke of the-valve attains apredetermined value.

7. An apparatus for applying a scale-preventing agent to the watersupply of an instantaneous water heater, comprising, in combination, asource of water under pressure, a suction device operated by the water,a suction line connecting said suction device with a source ofscale-preventing agent, a deviceregulating the quantity of water flowingthrough the water heater, and a valve in said suction line operable bythe pressure therein and which is operatively coupled with said device.

8. An apparatus for applying a scale-preventing agent to the watersupply of an instantaneous water heater, comprising, in combination, asource of water under pressure, a suction device operated by the water,a suction line connecting said suction device with a source ofscale-preventing agent, and a valve in said suction line operable by thepressure therein, a device regulating the quantity of water flowingthrough the water heater, and a spring clutch operatively coupling saidvalve with said device.

9. An apparatus for applying a scale-preventing agent to the watersupply of a water heater, comprising in combination, a source of waterunder pressure, a suction device operated by the flow of water to saidheater and having a conduit'opening into the path of said water, asuction line connecting said suction device with a source ofscale-preventing agent, and means controlled by the pressure in saidsuction line for controlling said suction line whereby the supply ofscale-preventing agent to said suction device is increased when thesupply of water to the heater is decreased and the supply ofscale-preventing agent to tile suction device is decreased when the flowof water to the heater is increased.

10. An apparatus for applying a scale-preventing agent to the watersupply of a water heater,

comprising, in combination, a source of water under pressure connectedto said heater, a source of scale-preventing agent connected to saidwater source, and 'means controlled by the flow of water to said heaterfor supplying scale-preventing agent to the water fiowingv to saidheater in inverse proportion to the intensity of said flow.

GEORG HEGWEIN.

